two-time
verb /ˈtuː taɪm/
  /ˈtuː taɪm/
(informal)Verb Forms
| present simple I / you / we / they two-time |    /ˈtuː taɪm/   /ˈtuː taɪm/  | 
| he / she / it two-times |    /ˈtuː taɪmz/   /ˈtuː taɪmz/  | 
| past simple two-timed |    /ˈtuː taɪmd/   /ˈtuː taɪmd/  | 
| past participle two-timed |    /ˈtuː taɪmd/   /ˈtuː taɪmd/  | 
| -ing form two-timing |    /ˈtuː taɪmɪŋ/   /ˈtuː taɪmɪŋ/  | 
- two-time somebody to not be faithful to a person you have a relationship with, especially a sexual one, by having a secret relationship with somebody else at the same time
- Are you sure he's not two-timing you?